A conventional liquid crystal display panel mainly includes a pair of glass substrates, a liquid crystal layer provided between the glass substrates, electrodes provided to the respective glass substrates, and polarizing plates attached to the respective glass substrates. According to such a liquid crystal display panel, light emitted from a backlight passes through the polarizing plates and the liquid crystal layer, and an image is recognized by a contrast appearing on a screen. However, before reaching a display screen, much of the light from the backlight is lost by being absorbed and reflected. This causes a decrease in light use efficiency. In particular, an optical loss occurring in the polarizing plates greatly affects a decrease in light use efficiency.
Patent Literature 1 discloses an optical device which includes flakes suspended in a fluid host and selectively switches optical properties. According to the optical device, orientations of the flakes are changed by a change in electric field to be applied to the fluid host. This causes the optical properties to be switched. According to this configuration, it is possible to omit the polarizing plates and, therefore possible to increase the light use efficiency, as compared with the liquid crystal display panel.